1. Field of the Invention
The present invention relates generally to an apparatus for visually indicating a current location of a vehicle. More particularly, the invention relates to an improved apparatus for electronically determining and visually indicating a current location of an automotive vehicle and the like so as to provide a visual display of combined information on a current status of the vehicle, such as a current location, a path of travel, etc., for the driver or operator of the vehicle.
2. Description of Relevant Art
In order to prevent the driver or operator of an automotive vehicle or the like from losing his way while driving such as at night or in unfamiliar surroundings away from his desired route of travel, there have been proposed a variety of apparatus which are specifically designed to provide the driver with suitable ready guidance relating to the vehicle's current status of travel with reference to the desired course of travel from time to time during travel, by indicating continuously or discretely a due current position or the like information on the vehicle by way of an indication panel or display screen including a related area or road map or the like disposed at the driver's seat.
With respect to the conventional apparatus for visually indicating a current location of an automotive vehicle for use as described above, in a typical construction a current travel distance of a vehicle is detected by way of distance detecting means in accordance with the vehicle's current travel speed and travel time, and a current bearing and a current quantity of azimuthal deviation of the vehicle are detected by bearing detecting means. A current location of the vehicle along its travel route is obtained from arithmetical operation on the basis of the thus-obtained route detection data, the result of which arithmetic operation is stored for visual indication on a display in the form of spot information which varies from time to time during travel of the vehicle, on a display screen on which there has been previously disposed a suitable road map which may be printed on a transparent sheet or the like. The driver of the vehicle may thereby comparatively review the thus-indicated visual information and the geographical indication by way of the map sheet so as to visually confirm the current location of the vehicle along its travel route.
With such a typical construction of the apparatus for use as described above, however, it is commonly required of the driver to select in advance a specific map sheet suitable for his particular route of travel or location from amongst a multiplicity or set of maps for placement upon the display screen. Such selection can prove to be an intricate and troublesome job which is likely to become more burdensome when a plurality of map sheets must be replaced during a relatively long distance trip. Further, it is possible that the map sheet may become loose and slip away from its due position upon the display screen, thus resulting in an improper or erroneous indication of a current location of the vehicle, and possibly even total uselessness.
The present invention effectively overcomes the above-described inconveniences and difficulties attendant the conventional location detecting apparatus for use in an automotive vehicle.